Tie Fan

Association between CYP2D6 *10 genotype and survival of breast cancer patients receiving tamoxifen treatment

BACKGROUND Human cytochrome P450 2D6 (CYP2D6) genotype may affect the efficacy of tamoxifen treatment in Caucasian women with breast cancer. The most common polymorphism of CYP2D6 in Chinese women is variant 10 (188 C to T). PATIENTS AND METHODS Tamoxifen and 4-hydroxytamoxifen (4OHtam) were measured in the serum of 37 women with breast cancer who were receiving tamoxifen treatment. The association between CYP2D6 *10 genotype and survival was determined in a cohort of 293 women with breast cancer who received tamoxifen (n = 152) or who did not (n = 141). RESULTS The serum 4OHtam concentrations were significantly lower in women with the CYP2D6 *10 homozygous variant T/T genotype than in those with the homozygous wild-type C/C genotype (P = 0.04). Among tamoxifen-treated women, women with the T/T genotype had a significantly worse disease-free survival (DFS) than those with the C/C or C/T genotype, and the T/T genotype remained an independent prognostic factor of DFS in multivariate analysis (hazard ratio = 4.7; 95% confidence interval = 1.1-20.0; P = 0.04). Among women who did not receive tamoxifen, there was no significant association between CYP2D6 *10 genotype and survival. CONCLUSION In tamoxifen-treated patients, women with the CYP2D6 *10 T/T genotype have a lower 4OHtam level in the serum and a worse clinical outcome.

Promoter methylation of BRCA1 in triple-negative breast cancer predicts sensitivity to adjuvant chemotherapy

BACKGROUND BRCA1 function is inactivated through BRCA1 promoter methylation in a substantial number of triple-negative breast cancers. We investigated the impact of BRCA1-methylation status on the efficacy of adjuvant chemotherapy in patients with triple-negative breast cancer or with non-triple-negative breast cancer. METHODS BRCA1 promoter methylation was assessed in 1163 unselected breast cancer patients. Methylation was evaluated using a methylation-specific PCR (MSP) assay. RESULTS In the subgroup of 167 triple-negative breast cancer patients who received adjuvant chemotherapy, patients with BRCA1-methylated tumors had a superior 10-year disease-free survival (DFS)(78% versus 55%, P = 0.009) and 10-year disease-specific survival (DSS) (85% versus 69%, P = 0.024) than those with BRCA1-unmethylated tumors, and BRCA1 methylation was an independent favorable predictor of DFS and DSS in a multivariate analysis in this subgroup [DFS: hazard ratio (HR) = 0.45; 95% confidence interval (CI) 0.24-0.84; P = 0.019; DSS: HR = 0.43; 95% CI = 0.19-0.95; P = 0.044]. In contrast, in 675 non-triple-negative breast cancer patients who received adjuvant chemotherapy, BRCA1 methylation was an unfavorable predictor of DFS and DSS in univariate analysis (DFS: HR = 1.56; 95% CI 1.16-2.12; P = 0.003; DSS: HR = 1.53; 95% CI = 1.05-2.21; P = 0.026). CONCLUSIONS Triple-negative breast cancer patients with BRCA1-methylated tumors are sensitive to adjuvant chemotherapy and have a favorable survival compared with patients with BRCA1-unmethylated triple-negative tumors.

Mutations in RECQL Gene Are Associated with Predisposition to Breast Cancer.

The genetic cause for approximately 80% of familial breast cancer patients is unknown. Here, by sequencing the entire exomes of nine early-onset familial breast cancer patients without BRCA1/2 mutations (diagnosed with breast cancer at or before the age of 35) we found that two index cases carried a potentially deleterious mutation in the RECQL gene (RecQ helicase-like; chr12p12). Recent studies suggested that RECQL is involved in DNA double-strand break repair and it plays an important role in the maintenance of genomic stability. Therefore, we further screened the RECQL gene in an additional 439 unrelated familial breast cancer patients. In total, we found three nonsense mutations leading to a truncated protein of RECQL (p.L128X, p.W172X, and p.Q266X), one mutation affecting mRNA splicing (c.395-2A>G), and five missense mutations disrupting the helicase activity of RECQL (p.A195S, p.R215Q, p.R455C, p.M458K, and p.T562I), as evaluated through an in vitro helicase assay. Taken together, 9 out of 448 BRCA-negative familial breast cancer patients carried a pathogenic mutation of the RECQL gene compared with one of the 1,588 controls (P = 9.14×10-6). Our findings suggest that RECQL is a potential breast cancer susceptibility gene and that mutations in this gene contribute to familial breast cancer development.

BRCA1 germline mutations and tumor characteristics in Chinese women with familial or early-onset breast cancer

The data related to BRCA1 germline mutation in Chinese women with familial breast cancer is increasing. However, little is known the frequency of BRCA1 mutations in Chinese women with familial or early-onset breast cancer from Northern China, and few studies are available to investigate the clinicopathological characteristics of BRCA1 tumors in Chinese women. In this study, we detected germline mutations in BRCA1 in a cohort of 139 breast cancer patients who either have a family history of breast cancer (n = 68) or whose tumors are diagnosed at or before the age of 35 (n = 71) from Northern China. A total of 6 deleterious BRCA1 mutations were identified in this cohort, 4 of which (5587-1 del8, 3887 del AG, IVS21 + 1delG, and 2129 ins TG) are novel and one mutation (3478del5) detected in this study was only reported in Chinese population. The frequency of BRCA1 mutations in women with familial or early-onset breast cancer was 5.9% (4/68) or 2.8% (2/71) in this cohort, respectively; but the mutations were detected in 4 of 16(25.0%) familial breast cancer patients whose tumors were diagnosed before the age of 40. Moreover, BRCA1 mutation tumors tended to be high histological grade, and to be negative for ER, PgR, and Her-2 compared with tumors without BRCA1 mutations. Our study suggests that Chinese women with a family history of breast cancer whose tumors are diagnosed before age of 40 would be a suitable candidate for BRCA1 testing; and BRCA1 tumors in Chinese women exhibit an aggressive phenotype.

RAD51C germline mutations in Chinese women with familial breast cancer

To the Editor,Germline mutations in high penetrance breast cancer sus-ceptibility genes, BRCA1 and BRCA2, account for onlyapproximately 10% of Chinese familial breast cancers [1],indicating other susceptibility genes related to Chinesefamilial breast cancer may exist. RAD51C gene (Ras-related associated with diabetes) is located on chromosome17q23, a region that was found to be frequently amplifiedin breast tumors [2, 3]. RAD51C gene is a member of theRAD51 family and plays an essential role in homologousrecombination, DNA damage sensitivity, genomic integ-rity, embryonic development, activation of cell cyclecheckpoint kinase 2 (CHK2), and cell cycle arrest inresponse to DNA damage [4–8].Recently, a biallelic missense mutation in the RAD51Cgene was found in a family from Pakistan with Fanconianemia-like disorder [9]. In an accompanying article, sixmonoallelic deleterious mutations in the RAD51C genewere found in 480 BRCA1/2-negative breast/ovarian cancerfamilies from Germany [10]. This study provides the firstevidence to show that the RAD51C is a breast cancersusceptibility gene. Thus, the RAD51C gene may deserveto be comprehensively screened as a breast cancer sus-ceptibility gene in other populations.In this study, we screened the entire coding regions andexon–intron boundaries of the RAD51C gene in 273 Chi-nese women with familial breast cancer who do not carrymutations in BRCA1 and BRCA2 genes by polymerasechain reaction (PCR)-sequencing. Familial breast cancercases were from the Breast Center, Peking UniversityCancer Hospital from July 2006 to May 2010. The criteriaof familial breast cancer are (1) patients have at least one ormore first- or second-degree relatives affected with breastcancer and/or ovarian cancer regardless of age and (2)bilateral breast cancer regardless of age. Four hundredsseventy-five healthy Chinese women serve as controls.Both of the cases and controls are Han Chinese women andreside in the north of China. The whole coding sequencesof RAD51C were amplified using nine sets of primersdescribed elsewhere with a minor modification [10]. Allfragments were sequenced using BigDye Terminator CycleSequencing Kit and ABI 3730 automated sequencer(Applied Biosystems, Foster City, CA). Each mutation wasconfirmed by duplicate.In total, we detected eight germline sequence variants inthe RAD51C gene in the 273 BRCA1/2-negative familialbreast cancer cases. Among them, three were non-codingvariants and five were coding variants (Table 1). None ofthem were previously reported. Of the coding variants, onewas synomenous and four were non-synomenous. Amongthe four amino-acid substitution variants, 4C[G (R2G) waslocated in exon 1, 635G[A (R212H) and 644A[G(D215G) in exon 4, and 882G[C (Q294H) in exon 6. Themissense variants R2G, D215G, and Q294H were detectedin one index case, whereas R212H was detected in twounrelated cases. We then screened the four missense vari-ants in 475 healthy controls. The variant R212H was foundin two healthy individuals, indicating this variant wasunlikely to be pathogenic. In contrast, none of the

Association between the HER2 Ile655Val Polymorphism and Response to Trastuzumab in Women with Operable Primary Breast Cancer

BACKGROUND Human epidermal growth factor receptor 2 (HER2) Ile655Val polymorphism may affect the efficacy of trastuzumab treatment of breast cancer. PATIENTS AND METHODS HER2 Ile655Val polymorphism was determined in 4167 patients with primary breast cancer using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. We investigated the associations between the HER2 Ile655Val polymorphism and clinical outcomes in women with HER2-negative breast cancer and with HER2-positive breast cancer who received trastuzumab or who did not. RESULTS At a median follow-up of 44 months, HER2 Ile655Val polymorphism was not significantly associated with survival either in the entire study population of 4167 patients or in 2976 HER2-negative breast cancer patients. Among 816 HER2-positive patients who received adjuvant chemotherapy and/or endocrine therapy without trastuzumab treatment, patients with the Val/Ile or the Val/Val genotype had a significantly worse disease-free survival (DFS) and distant DFS (DDFS) than those with the Ile/Ile genotype (DFS, adjusted hazard ratio [HR] 1.5; 95% confidence interval [CI] 1.0-2.3; P = 0.037; DDFS, adjusted HR 1.9; 95% CI 1.2-2.9 P = 0.005). In contrast, among 212 HER2-positive patients who received chemotherapy in combination with trastuzumab treatment, patients with the Val/Ile or the Val/Val genotype had a significantly better DFS and DDFS than those with the Ile/Ile genotype (5-year DFS, 100% versus 83%; P = 0.008; 5-year DDFS, 100% versus 89%; P = 0.031). CONCLUSIONS HER2 Ile655Val polymorphism affects the function of HER2 gene only restricted in HER2-positive breast cancers. HER2-positive breast cancer patients with the Val variant have an aggressive phenotype, but are sensitive to trastuzumab treatment.

Prevalence of BRCA1 mutations and responses to neoadjuvant chemotherapy among BRCA1 carriers and non-carriers with triple-negative breast cancer

BACKGROUND The frequency of BRCA1 germline mutations among Chinese women with triple-negative breast cancer is unclear, and the association between BRCA1 mutations and the response to neoadjuvant chemotherapy in women with triple-negative breast cancer has not been determined. PATIENTS AND METHODS Nine hundred and fifty-six triple-negative breast cancer patients were treated at our institute between 2003 and 2012; we tested the BRCA1/2 mutations for 956 patients and 953 patients in this cohort, respectively. Among the 956 patients, 652 patients received neoadjuvant chemotherapy. RESULTS In this cohort, 7.1% (68/956) and 2.3% (22/953) of patients carried a BRCA1 or BRCA2 mutation, respectively. The BRCA1/2 mutation rates were 10.5% and 3.0% among the patients who were diagnosed at or before the age of 50 in this cohort, respectively. The pCR (pathologic complete response) rate was 31.6% in the 652 patients who received neoadjuvant chemotherapy. BRCA1 carriers had a significantly higher pCR rate than non-carriers (BRCA1 carriers versus non-carriers, 53.8% versus 29.7%, P < 0.001). Among women treated with anthracycline with or without taxane regimens, the pCR rate was 57.1% for BRCA1 carriers, 29.0% for non-carriers (P < 0.001); among women treated with taxane regimens, the pCR rate was 40.0% for BRCA1 carriers, 32.9% for non-carriers (P = 0.73). At a median follow-up of 43 months, the recurrence-free survival was similar between BRCA1 carriers and non-carriers among the 947 patients of this study (adjusted hazard ratio = 0.92; 95% confidence interval: 0.45-1.90; P = 0.82). CONCLUSIONS Chinese women with triple-negative breast cancer who are diagnosed at or before age of 50 are candidates for BRCA1 genetic testing. Among triple-negative breast cancer patients, BRCA1 carriers are more likely to respond to neoadjuvant anthracycline-based regimens than are non-carriers.

HER2 and response to anthracycline-based neoadjuvant chemotherapy in breast cancer

BACKGROUND The predictive role of human epidermal growth factor receptor 2 (HER2) to adjuvant anthracycline-based chemotherapy remains controversial. Here, we investigated the association between HER2 status and pathological response in breast cancer patients who received neoadjuvant anthracycline-based regimens. PATIENTS AND METHODS Women (n = 538) with operable primary breast cancer received neoadjuvant anthracycline-based chemotherapy. Pathological complete response (pCR) was defined as no invasive breast tumor cells in breast after completion of neoadjuvant chemotherapy. HER2 status was determined by immunohistochemistry and/or by fluorescence in situ hybridization in core biopsy breast cancer tissue obtained before initiation of neoadjuvant chemotherapy. RESULTS In this cohort of 538 patients, 23.9% of patients achieved a pCR in their breast. HER2-positive tumors had a lower rate of pCR than did HER2-negative tumors (14.7% versus 25.7%, P = 0.013); negative HER2 status remained as an independent favorable predictor of pCR after adjusted for age, estrogen receptor, progesterone receptor, tumor size, chemotherapy cycles, and tumor grade in a multivariate analysis (odds ratio = 3.14; 95% confidence interval = 1.60-6.16, P = 0.001). Furthermore, patients with a pCR had a higher 3-year disease-free survival (DFS) rate than did patients without a pCR (P = 0.007). CONCLUSION Women with HER2-negative breast cancers rather than HER2-positive tumors benefit from anthracycline-based neoadjuvant chemotherapy.

A recurrent CHEK2 p.H371Y mutation is associated with breast cancer risk in Chinese women.

The association between the CHEK2 and breast cancer risk in Chinese women is unknown. Here, we screened the full CHEK2 coding sequence in 118 Chinese familial breast cancer cases who are negative for mutations in BRCA1 and BRCA2, one recurrent mutation, CHEK2 c.1111C>T (p.H371Y), was identified in five index cases in this cohort. Functional analysis suggested that CHEK2 p.H371Y was a pathogenic mutation that resulted in decreased kinase activity. We further screened the CHEK2 p.H371Y mutation in 909 unselected breast cancer cases and 1,228 healthy individuals. The frequencies of the CHEK2 p.H371Y in familial and unselected breast cancer cases and controls were 4.24% (5/118), 1.76% (16/909), and 0.73% (9/1228), respectively. The p.H371Y mutation was significantly associated with increased breast cancer risk in unselected breast cancer (odds ratio [OR] 2.43, 95% confidence interval [CI] 1.07–5.52, P = 0.034). Our results indicate that the recurrent mutation, p.H371Y, confers a moderate risk of breast cancer in Chinese women. Hum Mutat 32:1–4, 2011.

Effect of p53 codon 72 genotype on breast cancer survival depends on p53 gene status

In vitro studies suggest that p53 codon 72 genotype alters the apoptotic capacity of p53 protein, with the 72 arginine (R) form of wild‐type p53 harboring a greater apoptosis‐inducing potential than the 72 proline (P) variant. The aim of this study was to investigate whether the association between the p53 codon 72 genotype and breast cancer survival was modified by p53 gene status. In our study, we examined the p53 codon 72 genotype and p53 mutations (through exons 4–9) in paraffin‐embedded specimens from 414 breast cancer patients with a median follow‐up of 8.2 years. We report that the p53 codon 72 genotype was significantly associated with disease‐free survival (DFS, p = 0.02) but not with disease‐specific survival (DSS, p = 0.24) in the entire study population (n = 414). In contrast, the codon 72 genotype was strongly associated with both DFS (p = 0.001) and DSS (p = 0.04) among patients with a wild‐type p53 tumor (n = 346), patients with the P/P variant had worse DFS and DSS than did those with the P/R or R/R variant in this subgroup of patients. More importantly, as compared with the P/R or R/R variant, the P/P variant remained an independent prognostic factor of DFS among patients with a wild‐type p53 tumor (HR = 2.5; 95%CI = 1.4–4.4; p = 0.003). We conclude that the effect of p53 codon 72 genotype on breast cancer survival is dependent on p53 gene status, the P/P variant is strongly associated with poor prognosis among patients with a wild‐type p53 tumor.